Further whetting appetites for its new smartphone, Samsung tweeted an image this evening that is presumably the Galaxy S4, which is expected to be unveiled Thursday.

The very dark image, depicting only the upper left corner of what appears to be a smartphone with the familiar Samsung brand at the top, appeared on the South Korean electronics giant's official U.S. Twitter feed:

The tweet comes on the same day that Samsung launched the second in a series of teaser ads for the Galaxy S4. Today's installment involves Jeremy, the boy from the first ad, commenting on the contents of a box that ostensibly houses the Galaxy S4. He calls it "irresistible," "unreal," and "totally amazing."

At one point he says, "it's my favorite color," hinting that the Galaxy S4 could be available in many different versions. Like the first ad, this one ends with a "to be continued" message.

Samsung is expected launch its latest flagship smartphone at an event Thursday in New York City, and CNET will be there to cover the event every step of the way. Already, there has been a tremendous amount of attention and hype for the Galaxy S4, a phone expected to rival Apple's iPhone in popularity.

The Galaxy S4 is rumored to sport an eight-core Exynos processor, a separate eight-core graphics processing unit, a 4.99-inch Super Amoled display, 2GB of RAM, a 13-megapixel rear camera with 1080p video capability, a 2-megapixel front-facing camera, and the latest version of Android, known as 4.2.2 Jelly Bean.